Items of a related list represent relationships. They can illustrate the link between existing data records or be employed to create new records.
Related Lists Shortcuts & In Detail
The Related Lists shortcuts at the top of each contact provide an overview of the related lists including the number of entries (in brackets). Hover your cursor over one of these shortcuts to display the list of items.
Under the section showing the contact's details, you find the related lists. To add a new item to the list, use the buttons, e.g. New Task (1). To remove or edit an existing item, click the possible actions (2).
To change the displayed related lists and their order, click Edit Layout.
Once you are in the Edit Layout menu, you can customize the lists displayed and alter their order (using drag & drop).